Socket with pivotal contacts



March 24, 1970 J. J. LAZAR ET AL 3,503,035

SOCKET WITH PIVOTAL CONTACTS 3 Sheets-Sheet 1 Filed Nov. 8. 1966 INVENTORS Janos J. Lazar ussel 0. Bailey ATTORNEY March 24., 1970 J. J. LAZAR ET AL 3,5

SOCKET WITH PIVOTAL .CONTAGTS Filed Nov. 8, 1966 3 Sheets-Sheet 2 13 v a 2 l8 I 7 I I 4- 24 V v 5 I 24 4 32 33 2/ 2/ 33 Q r '2 22 I I l a I 23 l 26 25 27 1 I I! /9 It 1/ March 24, 1970 J. J. LAZAR ET AL 3,503,035

SOCKET WITH PIVOTAL ,CONTACTS Filed Nov. 8, 1966 s Sheets-Sheet 5 FRONT SIDE 30 BACK SIDE 3/ United States Patent O 3,503,035 SOCKET WITH PIVOTAL CONTACTS Janos J. Lazar, Dallas, and Russel 0. Bailey, Euless,

Tex., assignors to Texas Instruments Incorporated, Dallas, Tex., a corporation of Delaware Filed Nov. 8, 1966, Ser. No. 592,916 Int. 'Cl. Hlr 7/00, 23/36, 33/76, 23/00 US. Cl. 339--177 6 Claims ABSTRACT OF THE DISCLOSURE Disclosed is a coaxial socket having a pair of pivoting contacts which are activated when a device lead is inserted into one end of the socket and a locking pin is inserted into the other end of the socket, such that the contacts pivot to clamp the device lead in position and make electrical connection thereto and to the locking pin if desired.

This invention relates to electrical sockets, and more particularly to improvements in single and coaxial type sockets.

Sockets used for making connection between two or more electrical conductors generally employ spring-type or clamping-type contacts. However, the use of these spring-type contacts has several disadvantages. For example, the dependability of sockets using spring-type contacts often decreases with repeated use because after a spring type contact has been extended many times, it may lose the holding power to maintain the electrical connection. Furthermore, a force must be exerted on the conductor to insert it into and withdraw it from the socket, and another force, inherent in spring-type sockets, is necessary to assure that the electrical connection is maintained.

One use of sockets is in apparatus employed for testing transistors and integrated circuits. However, since such testing often involves high frequencies in the megaand gigi-Hertz range, noise picked up by unshielded conductors may become a problem. Therefore, a coaxial socket is desirable to avoid noise pickup.

Accordingly, one object of the present invention is to provide an improved socket which is usable in either single or coaxial connections.

A further object of the invention is to provide an improved socket which requires little or no force on a conductor to insert it into and withdraw it from the socket.

A still further object is to provide an improved socket which is capable of having a conductor inserted thereinto many times without reducing the clamping action to hold the conductor therein. A related object is to provide a socket which dependably makes an electrical connection to the conductor.

Various other objects, features and advantages of the invention will become apparent from the following detailed description when read in conjunction with the appended claims and attached drawings, in which:

FIGURE 1 is an exploded view of an entire socket in accordance with the present invention, showing the relationship of its various parts and assemblies in a preferred embodiment incorporating a plurality of sockets;

FIGURE 2 is a cross-section view taken longitudinally through the middle of an entire socket, with a device lead inserted into the front side and a locking pin inserted into the back side of the socket assembly;

Patented Mar. 24, 1970 FIGURE 3 is a cross-section view taken longitudinally through a socket with the angles exaggerated so as to particularly point out the principle involved in the present invention, and with a device lead inserted into the front side and with the locking pin in position to be inserted into the back side,

FIGURE 4 is identical to FIGURE 3 except that the locking pin is shown inserted into the back side of the socket; while FIGURE 5 is a representation showing the relationship of the parts incorporated in the socket assembly as if they were mounted in an invisible encasement.

The unique feature of the present invention is the use, in the socket, of contacting members which pivot. The primary advantage of such members is that a device lead, such as a transistor lead, for example, can be inserted into the socket without exerting any force upon the lead. Another advantage is that, because the con tacting members pivot, they can be made to clamp onto the device lead by means of a locking pin which causes the contacting members to lock the device lead and thereby hold it securely in place and make a very reliable electrical connection to the contacting members.

The socket has two assemblies: a socket assembly and a locking assembly. The socket assembly has two identical sides; for convenience, the side into which the device lead is inserted is called the front side, the other is called the back side (see FIGURE 3). In the use of the socket, a device lead is inserted into the front side of the socket assembly, and a pin of the locking assembly is inserted into the back side, thereby locking the device lead into the socket and making a good electrical connection between the device lead and the socket contacts.

The particular embodiment of the invention shown in the accompanying drawings and described herein is a coaxial construction; however, no limitation to such construction is intended as the invention can be equally utilized in a regular socket connection by a simple modification as hereinafter described. Other embodiments also will be apparent to those skilled in the: art.

Referring now to the figures of the drawings, wherein identical designations in the different views refer to identical parts, the coaxial socket assembly generally designated by number 50 (of FIGURE 1) comprises the inner pivoted contacts 12, the pivot rods 21 and the assembly body 18, and, in the particular embodiment herein described by way of example, the outer conductor 14 and the dielectric sleeve 13 therewithin. The two contacts 12 constituting the inner conductor of the coaxial socket are made from a hard conducting material such as, for example an alloy of copper and beryllium. The juxtaposed faces of contacts 12 have a slight triangular taper 22 which acts as a bearing, allowing them to rotate over a small angle about the pivot rods 21, as illustrated in exaggerated form in FIGURE 3. In addition to the triangular taper on the juxtaposed sides of contacts 12, a semi-cylindrical slot 20 is cut from each end of each contact to accommodate the device lead 11 on the front side 30 and the locking pin 15 on the back side 31 of the socket. Notches 32 are made on the outside, or nonjuxtaposed side of each contact 12 to fit the pivot rods 21.

The pivot rods 21 about a pair of which a set of contacts 12 rotates, act as fulcrums to allow said contacts to rotate, and also act as retainers to hold the socket assembly in place in the assembly body 18. These pivot rods, in a coaxial socket, are made of an insulating material such as glass so as not to cause an electrical short between the inner conductor 12 and outer conductor 14. It should be noted that if there is an array of similar inner contacts 12 and outer conductors 14 across the assembly body 18, one pair of pivot rods 21 made of insulating material will hold the conductors in place and keep each pair from being shorted. On the other hand, if there is but one pair of inner contacts 12 in the body and no associated outer contacts 14, rods 21 need not be made of an insulating material.

Outer conductor 14, made of copper, for example, and a dielectric sleeve 13 within it made of a material such as Teflon, are mounted over an associated pair of inner con tacts 12 in the assembly block 18 and in the position indicated in FIGURES 1, 2 and (not shown in FIGURES 3 and 4 which merely illustrate the locking principle of the invention). Notches 33 are made in the outer conductor 14 and dielectric sleeve 13 in such a manner that the pivot rods 21 can fit into the notches 32 cut in the pivoting contacts 12. A space 24 (shown in FIGURE 5) between the dielectric 13 and contacts 12 is provided to avoid the rotation of these contacts from being restricted. The back side of outer conductor 14 is made fiush with the back side face of the assembly body 18 because electrical contact is made to this outer conductor by the outer conductor 17 of the locking assembly.

As shown in FIGURES 1 and 2, the locking assembly is comprised of an assembly body 19, a locking pin 15, and, in this particular embodiment, an outer conductor 17 and dielectric sleeve 16. The locking pin 15 is encased by the dielectric sleeve 16 which, in turn, is encased in the outer conductor 17. This ensemble is mounted in the assembly body 19, and is held in place by retaining flanges 25, 27 and 26 (shown particularly in FIGURE 2), by a bend 28 in the outer conductor, and by an expansion 29 of the locking pin 15 in the back side thereof.

The locking pin 15 is constructed with a tapered end 23 to be inserted into the back side 31 of an associated pair of contacts 12 (see FIGURE 3). This taper should be small enough to allow the pin to be fully inserted into the contacts, but large enough to cause sufiicient clamping of the device lead 11 in the front side of the contacts. The electrical connection is made from the device lead 11 inserted in the front side of a pair of contacts 12, through the locking pin 15 which extends through the entire body 19 and thence, for example, to a lead (not shown) of a testing device connected to the bank side of locking pin 15. Also in this position, the outer conductor 14 of the socket and locking assemblies are in close proximity, if not touching. At the high frequencies used in integrated circuit and transistor tests, a ground plane would be established between the two outer conductors even if they were not touching. This ground plane would be effective in partially grounding the outer conductor of the socket assembly.

The operation of the socket, as particularly pointed out in FIGURES 3 and 4 in which the angles of pivot have been exaggerated to particularly point out the invention, is as follows: A device lead 11 is inserted into the slot an the front side 30 of the socket. The locking pin 15 is inserted into the back side 31 of the socket, causing the pivot contacts 12 to rotate, much like a clothespin, on the pivot rods 21 (as shown by the arrows 34 on FIGURE 4). Because of the taper 23 on the end of the locking pin 15, the contacts 12 spread on the back side 31 of the socket and clamp on the front side 30 of the socket, thereay locking the device lead 11 firmly into the socket. An electrical connection is thereby made from the locking pin 15 through the rigid contacts 12 to the device lead 11.

In connection with uses in transistor and integrated :ircuit testing applications, it is often desired that the co axial sockets used have a certain electrical impedance, for example 20 ohms. To this end, applicants have found that by using Palimey 7 made by the J. M. Ney Co. for the rigid contacts 12, Teflon of inside diameter 0.070 inch and outside diameter 0.93 inch for the dielectric sleeve 13, and copper of inside diameter 0.094 inch and outside diameter of 0.104 inch for the outside conductor 14, along with pivot rods 21 composed of 614 Alismag made by the American Lava Company, and 0.125 inch spacing center to center between adjacent sockets, a socket of 20 ohms impedance can be constructed.

By using Berilco 25, a beryllium-copper combination, for the locking pin 15, Teflon of inside diameter 0.040 inch and outside diameter 0.093 inch for the dielectric material 16, and copper of inside radius 0.094 inch and outside radius of 0.104 inch ,an impedance of 50 ohms can be obtained for a 0.125 inch spacing between adjacent coaxial locking pins.

Although the present invention has been described in detail, various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. An electrical coaxial socket comprising in combination an inner conductor composed of a plurality of members pivoting about a mutually contacting surface, at least one pivot member in engagement with said inner conductor, a lead inserted into one end of said inner conductor, a pin insertable into the other end of said inner conductor, thereby to cause said plurality of members of said inner conductor to pivot about said mutually contacting surface and said at least one pivot member and lock said lead to said inner conductor, a conducting material surrounding said inner conductor except at the ends thereof, and a dielectric material insulating said inner conductor from said conducting material surrounding said inner conductor.

2. An electrical socket according to claim 1 wherein a plurality of said sockets are embodied into a single assembly.

3. An electrical coaxial socket comprising in combination an inner conductor composed of a plurality of members pivoting about a mutually contacting surface, at least one pivot member in engagement with said inner conductor, a conductive lead inserted into one end of said inner conductor, a pin insertable into the other end of said inner conductor, thereby to cause said plurality of members of said inner conductor to pivot about said mutually contacting surface and said at least one pivot member and lock said conductive lead to said inner conductor, a conducting material surrounding said inner conductor except at the ends thereof, a dielectric material insulating said inner conductor from said conducting material surrounding said inner conductor, whereby when another lead is connected to said pin, a continuous conductive path is established from said conductive lead, through said inner conductor, said pin, and to and including said other lead.

4. An electrical socket comprising a body, a pair of contacts within said body, members in said body on opposite sides of said contacts, said contacts mounted for pivotal movement about said members, mutually contacting surfaces on said contacts positioned between said members about which said contacts rock during pivoting movement thereof, said contacts forming slots extending inwardly toward said contacting surfaces, whereby when means are inserted into the slot in one end of said pair of contacts to lock said pair of contacts to a lead inserted in the slot in the other end, said contacts rock about said mutually contacting surfaces and said fixed members.

5. An electrical socket comprising a body, a pair of conductors within said body, members in said body on opposite sides of said conductors, said conductors being mounted for pivotal movement about said members, mutually contacting surfaces on said conductors positioned between said members about which said conductors rock during pivoting movement thereof, said conductors forming slots extending inwardly toward said contacting surfaces, whereby when means are inserted into the slot in one end of said pair of conductors to lock said pair of conductors to a lead inserted in the slot in the other References (ited UNITED STATES PATENTS Bickham 339-64 Rubel 33964 Wills 33964 X Lehr et al. W 339-59 Yarrick et a1. 33964 Newman et a1. 339177 X Johanson et a1. 339177 X Rudd 339-266 X 5 MARVIN A. CHAMPION, Primary Examiner J. H. MCGLYNN, Assistant Examiner U.S. Cl. X.R. 

